The word “Strobe” is derived from the Greek word strobos, which translates into English as “act of whirling.” Strobing or whirling animation toys and devices were first invented over 175 years ago wherein a rapid succession of individual images were extracted from a spinning printed disk or drum thereby creating the visual illusion of realistic motion. Some are still in use today. The method of image extraction in these devices is customarily achieved either by viewing the whirling images through sweeping slots or by illuminating the whirling images with synchronized light flashes. The methods are alike in that they create the illusion of motion by visually “freezing” the whirling, blurring images one by one, revealing each image as clear and distinct for a fleeting moment before replacing that image with the next.
In 1830, Belgian physicist Joseph Plateau invented the Phenakistoscope, a radially-slotted disk with a succession of drawings arranged concentrically around its perimeter. The drawings appear to come to life and move when the disk is whirled on its axis by a handle and viewed in a mirror through the slots. Ten years later, in 1840, British scientist William Horner disclosed an improved slot animation toy that is referred to as a Zoetrope. The Zoetrope has a slotted drum with images or figures disposed therein such that the images or figures can be viewed through the slots. The images on the paper strips appeared to come to life and move when viewed directly through the slots as the drum is whirled on its pivoting axis. The Praxinoscope was invented in approximately 1877 by Charles-Émile Reynaud. As with the Zoetrope, a series of images is typically placed around the inner surface of a spinning cylinder. However, the narrow viewing slits of the Zoetrope are replaced with outwardly facing mirrors on a central hub. When the cylinder is rotated, the reflections of the images appear in rapid succession thereby producing the illusion of motion.
In the Phenakistoscope, the Zoetrope, and the Praxinoscope, there is usually a direct correlation between the number of drawings and the number of slots: 12 drawings for 12 slots, for example. With that, the subjects appear to maintain their relative location on the drum or disk while animating. Sometimes, such as by providing one more or one less figure than the number of slots or mirrors, the animating subjects can be made to appear to progress directionally as they animate thereby appearing to traverse around the disk or drum. In these devices, one complete animation cycle containing all of the figures is always completed in one full rotation of the whirling image device. Therefore, it behooves the artist to design looping animation cycles, such as a horse galloping, that appear natural when played repeatedly and continuously.
In 1930, MIT scientist Harold Edgerton advanced the art of stroboscopic animation by substituting an adjustable-rate flashing light, now referred to as a strobe light, trained on motorized whirling disks and drums with sequential images disposed thereon. This eliminated the need to peer through slots or look through mirrors and permitted free viewing of the animations for the first time. This method also dramatically expanded the range of animations that could be presented as the flash rate could easily be tuned to differently-designed whirling image configurations and devices, including those containing different numbers of animated drawings. In other words, the light could be made to flash 12 times per revolution of a whirling image device imprinted with 12 consecutive drawings, then adjusted to flash 13 times per revolution to make the image travel in one direction, then adjusted to flash 11 times per each revolution to make the image travel in the other direction. A different animation strip with 16 drawings could then be substituted, and the strobe light could then be adjusted to flash, for example, at the rate of 16 times per revolution.
Since the development of stroboscopic animation, a number of scientists and artists, including one of the present inventors, have devised strobe-lit animation devices and displays operative under these principles. In such devices and displays, a rotatable image device can be rotated by a motor at a constant or varying speed. Alternatively, it may be freely spun by hand so that it decreases in speed as it naturally slows to a stop.
In every such strobe-lit animation device, two elements have been required to achieve animation: 1) a rotating image device and 2) synchronization of the strobe light, such as with a separate, stationary referencing unit that cooperates with the whirling image device to produce synchronization. In a motorized rotatable image device, animation may be achieved by a physical electro-mechanical tether between these two elements. In a freely hand-spun device, these two elements may communicate wirelessly, such as through radio, magnets, or infra-red signals. Lacking any communication between the two, a manually- adjustable strobe light must be trained on the rotating image device to achieve animation.
The practiced user will appreciate that a hand-spun rotatable image device affords more user participation and thus more enjoyment than a motorized one. Further, as the rotating velocity of a hand-spun device naturally slows down along with the synchronized strobe light flash frequency, the progressive slowing in the animation itself is more entrancing than wherein it is maintained at a monotonous, constant speed. For example, when initially hand-spun, the device might present the animation of a furiously galloping horse. Then, as the whirling device slows, the horse's animation slows as well, presenting a more natural, relaxed, and realistic cadence of gallop, progressing to slow motion and finally stopping.
The resulting animations in these devices are delightful to view. Yet, without exception, the stroboscopic animation devices themselves are ungainly and difficult to employ because they invariably require the interaction of the two elements described above: the rotating image device and a separate, synchronized strobe light, typically in the form of a separate, stationary referencing unit. A self-contained, self-orienting, and self-strobing rotatable animation device would, therefore, represent a significant advance in the art.
The present inventors, each accomplished in the world of inventing and in relation to animation devices in particular, are uniquely situated to appreciate the challenges involved in devising of such an animation device and in conceiving of the necessary structural and operational details of a functional self-contained, self-orienting, self-strobing rotatable animation device. With U.S. Pat. No. 7,037,169 to Benedek et al. for a Rotating Toy with Rotation Measurement Means, a plurality of the present inventors disclosed a manually rotatable, self-orienting device that, simply described, utilizes an internal earth magnet compassing system within a spinning top to determine the North/South/East/West orientation of the top as it spins. This information is used to cause a spinning array of LEDs to paint stationary images of letters and numbers in space. Moreover, a co-inventor herein invented the Stroboscopic Animation System of U.S. Pat. No. 8,482,714. There, realistic animations are realized by employing a manually rotated top with interchangeable printed paper animation disks in combination with a separate, manually-adjustable flashing strobe light.
The present inventors therefore recognized that there has been a long-felt need for a completely self-contained, self-orienting, self-strobing, manually rotatable stroboscopic image animation device. Because such a device would be wholly free of dependence upon any external devices, including an external referencing device, it could be employed to the enjoyment of the user with unparalleled ease. In appreciating the foregoing need, the inventors comprehended that such a manually rotatable animation device would need to be North/South/East/West self-orienting and that it would need to exploit the acquired information to synchronize strobe lighting built into the device itself. Further, to accommodate a wide range of different animated subjects, the strobe light's flash rate mode would need to be adjustable, either automatically or by manual selection by the user.